maybe pepper, breathe deeply with its spicy smell, I think you'll be too busy coughing, can't afford to smoke then . After training yourself for some time, you may have the conditioned reflex--- smell the pepper, and cough instend of smoke.

Let's face it, herbal smoking mixtures will not cause you to quit smoking tobacco. Only you can stop. Smoking mixtures can aid in the process if you are ready. A variety of mixtures can be helpful like Lobelia .Ask a herbalist in your area for advice.

Maybe Marihuana?

yes because CO2 receiv and O2 released during photosynthesis working time.